The primary goal of the Environmental Modeling and Exposure Assessment Facility (EMEAF) is to facilitate the research efforts of Center investigators by providing a variety of services and equipment needed to understand the relationship between contaminants found in rural environments and their impact on human health. The EMEAF accomplishes this goal by offering Center investigators: [unreadable] A cost-effective instrumentation lending service, [unreadable] Guidance on modeling and display of contaminants and affected populations, [unreadable] Advice on initiating and conducting population-based studies, and [unreadable] Expertise in measuring environmental contaminants. In particular, the EMEAF provides essential support and direction to young investigators beginning to build research careers. The investigators and staff of the EMEAF consist of individuals with expertise in ambient air sampling, industrial hygiene practices, health physics, air dispersion modeling, computational fluid dynamics modeling, development of geographical information systems, epidemiological assessments, and chemical analytical methods. This team seeks to give essential support and direction to Center investigators in order to achieve the overall goals of the Center. Furthermore, the EMEAF provides a leadership role within the Center by aiding investigators in their efforts to identify and access appropriate study populations and health registries in order to effectively link environmental toxicant exposures with possible adverse health outcomes within populations. EMEAF staff will also work to increase the power of epidemiologic studies by improving methods to reduce exposure misclassification.